My invention relates to an apparatus for data transfer with two or more interchangeable tape cassettes or like tape assemblies in which data are stored with different recording characteristics, e.g. different formats or different recording densities, and which in consequence, demand different circuit means for data reproduction. More specifically, my invention pertains to a system incorporated in such compatible data transfer apparatus for discriminating between the two different types of tape assemblies as either of these is loaded in the apparatus, preparatory to the commencement of data transfer therewith. Typical examples of tape assemblies for use with the apparatus of my invention are multitrack magnetic tape cassettes for the storage of digitized audio signals.
An apparatus for data transfer with multitrack magnetic tape cassettes of the type under consideration is disclosed in U.S. Pat. No. 4,701,817 issued to Uemura and entitled, "Loading and Ejecting Mechanism for a Magnetic Tape Cassette Apparatus." In the field of magnetic tape media for the storage of digital data, attempts are being made for greater and greater storage capacities through an increase in recording density or in track density. Generally, the recording density becomes higher with an increase in the coercive force of the tape. There are commercially available today magnetic tape cassettes or other tape assemblies of distinctly different recording densities as well as of different formats. Thus the need arises for the provision of compatible data transfer apparatus which lends itself to use with two or more tape assemblies of different recording characteristics. Such compatible apparatus should permit the different tape assemblies to be loaded interchangeably therein, identify each loaded tape assembly, and adapt itself for data transfer with the particular type of tape assembly that has been identified as such.
I am aware that, particularly in the field of digital audio tape recorders or decks, a variety of methods and devices have been suggested for automatically identifying the recording density or format of each loaded tape assembly preparatory to the commencement of playback or recording. My objection to such known devices is that they are not so simple and inexpensive in construction as can be desired.